Photochemical smog is unique air pollution and causes highly attention in recent years. Photochemical smog obscures sight reducing atmospheric visibility. Ozone can reflect the degree of photochemical pollution. Serious photochemical smog pollution is harmful to both human and plants which needs to be dealt with seriously. Atmospheric visibility is an index reflecting the transparency of the atmosphere and determined by the concentration, size distribution and chemical compositions of the ambient aerosol. RSP blames for the formation of aerosols reducing the atmospheric visibility. The aim of this thesis is to ensure the main pollution sources for distant transport during the period of 2005-2011 in Hong Kong by conducting the HYSPLIT model simulations with meteorological data collected from GDAS1 and also make clear the long-term (2001-2011) trend of photochemical pollution and atmospheric visibility reduction in Tung Chung. Collect and compare data of 2001-2011 years under the NAAQS 1-hour and 8-hour ozone concentration standards and compare the maximum concentration of each year to explain the overall long-term ozone pollution trend, as well under the Hong Kong 24-hour standards of both SO₂ and RSP, the atmospheric visibility reduction can be better understood. Through simulations, analyze the main regional pollution sources and load the foundation of disposal following. Days with hourly ozone concentration (>250μg/m³) from 2005 to 2011 in Tung Chung are chosen to conduct the HYSPLIT model simulation. 1741 backward trajectories are selected to process the cluster analysis to classify these backward trajectories into 5 main clusters - Track 1: the first trajectory was from inland China; Track 2: the second one was also originated from inland China with higher transport speeds than Track 1; Track 3: the third was along the Eastern China coast; Track 4 was from Zhuhai，Macau and even the South China Sea with lower transport speeds than the others and Track 5 was generated from continental Asia. The air masses were carried by each trajectory: Track 2 (31%), followed by Track 1 (26%), Track 3 (20%), Track 4 (14%) and the last is Track 5 (9%). The regional pollution mainly comes from regions of inland China and China Eastern Coast with much highly industrialized. Seen from the long-term trend of photochemical pollutants, SO₂ and RSP, the peak value appeared around 2004 is related with the increased coal-fired power plants. However, since 2005, the trends go down with much lower concentrations of pollutants than 2004's, it is because the emission caps are released to those power plants. Some other controlling measures are also introduced in my thesis to help reduce concentrations of relevant pollutants and alleviate bad effects of these pollutions. This study can contribute to a better understanding of photochemical pollution and atmospheric visibility reduction in places under similar conditions of meteorological conditions and industrialized levels and make up the current photochemical pollution study in Tung Chung of Hong Kong.